Eleven products were tested. For the Diptheria Antitoxin, Epoetin Alfa Epogen, Tetanus Antitoxin, Interferon Alfa 2b Recombinant, G-CSF, and Streptokinase, the A. niger grew out in SCDM and FTM, thus showing that at this dilution (1 in 11), there was no fungistatic effect. For Influenza Virus Vaccine, Hepatitis B Vaccine Recombinant, Pneumococcal Vaccine Polyvalent, and Tetanus and Diptheria Toxoids Absorbed, the A. niger grew only in the bottles of FTM. This is an expected result since these products contain thimerosal, which thioglycollate neutralizes. The exception to this is the Hepatitis B Vaccine which only has formaldehyde listed in its protocol, not thimerosal, and did not grow out in SCDM. The Diptheria and Tetanus Toxoids and Pertussis Vaccine is the only product that would not allow the A. niger to grow in either media, not even at a product dilution of 1 in 50. Therefore, the sterility test for DTP, which used a dilution factor of approximately 1 in 80, will have to be checked at the dilution. We will continue this testing as time allows to be sure that products with preservative are being adequately diluted in the sterility test.